1. Field of the Invention
The present invention relates to an electrical connector, and more particularly to a socket connector for electrically interconnection with a pin grid array (PGA) package to a printed circuit board (PCB).
2. Description of Prior Arts
Integrated circuits (ICs) are becoming smaller, more complex, and more prevalent. It is common for a modern electronic appliance, such as a computer, to have several IC components attached to a circuit board. Each IC is generally delivered as an enclosed package with a pin grid array (PGA) interface. The PGA interface is a set of electrically conductive pins arranged in a pattern, where each pin is an electrical connection to the functional portion of the IC. In order to install the IC in an electronic appliance, the pins must be electrically connected to appliance's main circuit board. It is thus desirable for there to be a simple mechanism that permits the IC to be quickly and easily attached to the circuit board, while minimizing the risk of damage.
One device that permits a simple, fast connection between an IC and a circuit board is a Zero Insertion Force (ZIF) socket assembly. A ZIF socket assembly is a device having set of contacts in electrical connection with the circuit board, where the contacts are disposed in a set of sockets. The device is arranged such that the pins of the IC can be inserted into the sockets without touching the contacts so that the pins do not encounter frictional resistance as they are inserted. Subsequent to the insertion of the pins, the device brings the pins and contacts into electrical connection, such that electrical impulses can flow freely between the pins and the circuit board by way of the contacts.
A number of ZIF socket devices have been proposed. A typical ZIF socket assembly may utilize a plastic socket cover that is slidably movable on a plastic socket base between an open position and a closed position. Generally, an actuating mechanism is used to drive the cover and the base between the open and closed positions. One type of actuating mechanism according to the prior art is an eccentric cam shaft which is basically in the form of a screw member which is operated by an appropriate tool, such as a screwdriver. The eccentric cam shaft has an eccentric portion engageable with the socket cover and moving the socket cover relative to the socket base.
Generally, referring to FIG. 1, the ZIF socket assembly further includes a plate 27 that is retained in a recessed area 225 on a bottom of the socket base 22, wherein the plate 27 is formed of metal or another suitably hard materials to absorb forces created by the eccentric cam shaft, thereby protecting plastic area of the socket base 22 from cracking and giving the ZIF socket assembly a long-life span. More specifically, for some demands, the plate 27 has a rough surface facing the bottom of the recessed area and a slippery surface opposite to the rough surface facing exterior to be cooperated with other subassembly (not shown). However, since the conventional plate 27 is geometrical symmetry, the ZIF socket assembly is suffered from several drawbacks, and particularly, problem will be encountered in attempting to assemble the plate 27 to the recessed area 225 of the socket base 22. During the course of assembling, the rough surface of plate 27 is inclined to mistakenly face exterior without notice so as to wear and tear the subassembly, resulting in a shorten life of the subassembly.
In light of the problem, an improved socket connector is desired to overcome the drawback of the prior arts.